Black phosphorus quantum dots as multifunctional nanozymes for tumor photothermal/catalytic synergistic therapy

Nanozymes are nanomaterials with enzyme-like properties that have attracted significant interest owing to their high stability, easy preparation, and tunable catalytic properties, especially in the field of cancer therapy. However, the unfavorable catalytic effects of nanozymes in the acidic tumor microenvironment have limited their applications. Herein, we developed a biomimetic erythrocyte membrane-camouflaged ultrasmall black phosphorus quantum dots (BPQDs) nanozymes that simultaneously exhibited an exceptional near-infrared (NIR) photothermal property and dramatically photothermal-enhanced glucose oxidase (GOx)-like activity in the acidic tumor microenvironment. We demonstrated the engineered BPQDs gave a photothermal conversion efficiency of 28.9% that could rapidly heat the tumor up to 50 °C while effectively localized into tumors via homing peptide iRGD leading after intravenously injection. Meanwhile, the significantly enhanced GOx-like activity of BPQDs under NIR irradiation was capable of catalytical generating massive toxic reactive oxygen species via using cellular glucose. By combining the intrinsic photothermal property and the unique photothermal-enhanced GOx-like catalytic activity, the developed BPQDs were demonstrated to be an effective therapeutic strategy for inhibiting tumor growth in vivo. We believe that this work will provide a novel perspective for the development of nanozymes in tumor catalytic therapy.